1. Field of the Invention
The present invention relates to formation of trench structures over a substrate, and more particularly to a method of forming sub-lithographic trench structures.
2. Description of Background
Typical semiconductor computer memories are fabricated on semiconductor substrates consisting of arrays of large number of physical memory cells. The memory cells in these memory arrays are generally connected by conductive channels carrying electrical current between individual memory cells, the memory array, and a memory controller. These conductive channels are often referred to as “bit-lines” and “word-lines”. As memory cells and memory arrays have decreased in size, the conductive channels connecting forming the connections between the cells and array must also decrease in size.
Conductive channels formed on the substrate may be formed with a variety of methods. One common method is to deposit conductive material directly into a trench structure on the substrate. Often, methods used for trench structure formation include at least one step involving photolithography. The photolithographic methods employed for the formation of conductive channels and other structures formed on a substrate are typically limited by the wavelength of deep ultraviolet (DUV) a photolithographic tool uses. Thus, it is desirable to devise a method to form trench structures not limited by the specifications of the photolithographic tool being used.